Revert "Toggle user switcher in car QS footer."

This reverts commit df63d97e1a0d820d18e61681739e292025a6f315.

This commit will be replaced by ag/2690511, which implements the user
switcher using UserGridView instead.

Change-Id: I8f21f1dc1653834b3408e1c22a67d7787673185c
6 files changed